Normal Findings in CT and MRI E-Book

Torsten Bert Moeller

• Herausgeber: Thieme
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 147

Veröffentlichungsjahr: 1999

Beschreibung

The key for any beginning radiologist who wishes to recognize pathological findings is to first acquire an ability to distinguish them from normal ones. This outstanding guide gives beginning radiologists the tools they need to systematically approach and recognize normal MR and CT images.

Highlights include:

• Reference-quality images from the author's own teaching files show all standard normal findings as seen in CT and MRI
• Checklists in each section offer the reader a systematic way to approach the images
• Thorough guidelines to help beginning radiologists dictate their reports
• Lists of standard measurements and tips for ruling out pathology

Leseprobe

Normal Findings in CT and MRI

Torsten B. Moeller, M.D.Am Caritas-KrankenhausDillingen/SaarGermany

Emil Reif, M. D.Am Caritas-KrankenhausDillingen/SaarGermany

210 Illustrations

ThiemeStuttgart · New York 2000

Library of Congress Cataloging-in-Publication Data

Moeller, Torsten B.

[CT- und MRT-Normalbefunde. English]Normal findings in CT and MRI / Torsten B. Moller, Emil Reif. p. cm.Includes bibliographical references and index.ISBN 0-86577-864-7 (TNY). - ISBN 3-13-116521-9 (GTV)1. Tomography. 2. Magnetic resonance imaging. 3. Reference values (Medicine)4. Human anatomy. I. Reif, Emil. II. Title.[DNLM: 1. Magnetic Resonance Imaging. 2. Tomography, X-Ray

Computed. WN 185 M726c 1999a]RC78.7.T6M6413 1999616.07’57-dc21DNLM/DLCfor Library of Congress

99-33663CIP

This book is an authorized and revised translation of the 1st German edition published and copyrighted 1998 by Georg Thieme Verlag, Stuttgart, Germany. Title of the German edition: CT-und MRT-Normalbefunde

Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names, even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain. This book, including all parts thereof, is legally protected by copyright. Any use, exploitation, or commercialization outside the narrow limits set by copyright legislation, without the publisher’s consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

© 2000 Georg Thieme Verlag,Rüdigerstrasse 14,D-70469 Stuttgart, GermanyThieme New York, 333 Seventh Avenue,New York, NY 10001, USA

Typesetting by primustype R. Hurler GmbH, D-73274 Notzingen, Germany typeset on Textline/HerculesPro Cover design by Cyclus, Stuttgart Printed in Germany by Offizin Andersen Nexö, Leipzig

ISBN 3-13-116521-9 (GTV)

ISBN 0-86577-864-7 (TNY)

1 2 3 4 5 6

Important Note: Medicine is an ever-changing science undergoing continual development. Research and clinical experience are continually expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every effort to ensure that such references are in accordance with the state of knowledge at the time of production of the book.

Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of application stated in the book. Every user is requested to examine carefully the manufacturer’s leaflets accompanying each drug and to check, if necessary in consultation with a physician or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers differ from the statements made in the present book. Such examination is particularly important with drugs that are either rarely used or have been newly released on the market. Every dosage schedule or every form of application used is entirely at the user’s own risk and responsibility. The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed.

To my father, Alfred Moeller,in love and gratitude

Preface

This book, like its conventional counterpart Normal Findings in Radiography, deals with the apparently banal subject of the normal. It addresses the question of how to recognize what is normal and how to describe normal findings. These questions are as important in computed tomography and magnetic resonance imaging as in other modalities. Even “sectional imaging” is based on the classical approach of reading images and formulating findings.

This book follows the same format used in Normal Findings in Radiography. Each section starts with a brief descriptive interpretation of normal findings in the region of interest. Next comes a checklist that follows the sequence of the descriptive text and provides a systematic framework for image interpretation. Some of the checklist entries offer phrasing suggestions that may be helpful in the formulation of findings. Most sections conclude with a table of “Important Data” listing the normal ranges of values for the most important measurable parameters. Of course, the “normal findings” presented here can only assist the radiologist in formulating his or her own findings. But regardless of whether we are taking a brief look or conducting a detailed evaluation, the system that is used in radiological interpretation should be reflected in the clarity and precision of the findings. This book is intended to further that goal.

We express sincere thanks to Alexandra Kläser, Sabine Mattil, Tanja Metzger, Monjuri Paul, Pia Saar-Schneider, Gisela Wagner, and especially Brigitte Schild for their help in compiling the CT and MR images. We also thank our colleagues Dr. Markus Bach, Dr. Christoph Buntru, Dr. Wolfgang Theobald, Dr. Albert Schmitt, Dr. Karl-Ernst Schmitt, Dr. Heike Rochelmayer, Dr. Pattrick Rosar, Dr. Lutger Henke, Dr. Klaus Kuhnen, and Dr. Christa Weller-Schweizer for their help and many suggestions, which helped see the book to its completion.

Dillingen, 1999

Torsten B. MoellerEmil Reif

Table of Contents

Computed Tomography

CT: Head and Neck

Neurocranium

Pituitary

Petrous pyramids

Orbit

Paranasal sinuses

Cervical soft tissues

CT: Chest

Thoracic organs

CT: Abdomen

Upper abdominal organs

Liver

Pancreas

Kidneys

Adrenal glands

Female pelvis

Male pelvis

CT: Spinal Column

Cervical spine

Thoracic spine

Lumbar spine

Magnetic Resonance Imaging

MRI: Head and Neck

Neurocranium

Pituitary

Internal auditory canals, petrous pyramids

Orbit

Paranasal sinuses

Cervical soft tissues

MRI: Chest

Thoracic organs

Breast

MRI: Abdomen

Upper abdominal organs

Liver

Kidneys

Adrenal glands

Female pelvis

Male pelvis

Testes

MRI: Spinal Column

Cervical spine

Thoracic spine

Lumbar spine

Sacroiliac joints

MRI: Joints

Temporomandibular joint

Shoulder joint

Elbow joint

Wrist

Hip joint

Knee joint

Ankle and subtalar joints

MRI: Special Investigations

Cranial vessels

Cranial venous vessels

MR angiography of the renal arteries

Pelvic and lower limb vessels

MR cholangiopancreatography

Cervical arteries

References

Index

Computed Tomography

CT: Head and Neck

Neurocranium

The interhemispheric fissure is centered on the midline. The cerebrum and cerebellum show normal cortical sulcation.

The cerebral ventricles are of normal size and symmetrically arranged. There are no signs of increased intracranial pressure.

Normal development of the white matter and cortex, with normal density of the periventricular white matter.

The basal ganglia, internal capsule, corpus callosum, and thalamus appear normal.

The brain stem and cerebellum, if evaluable, also appear normal.

Sella and pituitary are normal. Parasellar structures are unremarkable.

There are no abnormalities in the cerebellopontine angle areas on both sides.

The paranasal sinuses and mastoid air cells are normally developed, clear, and pneumatized. The orbital contents are unremarkable. There are no abnormalities in the calvarium.

Interpretation

Normal cranial CT.

Checklist Interhemispheric fissure

• Centered on the midline

• No displacement

• Falx cerebri:

– Width

– Density (no calcifications)

Cortical sulcation

• Of cerebrum and cerebellum (arbor vitae):

– Configuration

– Number of sulci

– Width of sulci

– No coarsening of sulci

– No circumscribed narrowing or expansion

– Well-defined cisterns and cortical markings

Cerebral cortex

• Width

• Distribution (no ectopic tissue)

• Density (see below), no calcifications or hemorrhages

• No separation from the calvarium

• No abnormal fluid collection (convex or concave) between the cerebral cortex and calvarium

Ventricles

• Shape

• Size appropriate for age (see below)

• Symmetry (no unilateral or circumscribed enlargement)

• No signs of increased intracranial pressure (e.g., effaced sulci, narrowing or unilateral expansion of ventricles)

White matter

• Density (homogeneous, especially at periventricular sites—see below)

• No hypodensities (circumscribed, lacunar, or diffuse)

• No hyperdense changes (calcification, hemorrhage)

• Normal width in relation to cortex

Basal ganglia, internal and external capsule, thalamus Corpus callosum

• Position

• Size

• Delineation

• Density

• Configuration

• Size

• Density

Brain stem

• Shape

• Density (homogeneous)

• No focal abnormalities

Cerebellum

• General form (symmetry)

• Cortex (width, sulcation)

• White matter (homogeneous density)

Intracranial vessels

• Course

• Width

• No abnormal dilatation

• No vascular malformations

Sella and pituitary

• Size (see below)

• Configuration

• Density

• Borders

• Parasellar structures

Petrous pyramids

• Cerebellopontine angle area:

– Width and symmetry of bony portions of internal auditory canals (see below)

– CSF spaces symmetrical and of normal size, no masses

• Mastoid air cells, mastoid antrum

– Anatomy

– Pneumatization

– Borders (wall thickness, smooth contours with no discontinuities)

– No masses

– No fluid-dense opacification

• Cochlea and semicircular canals:

– Anatomy

– Configuration

– Smooth borders

Paranasal sinuses

• Anatomy

• Pneumatization

• Borders (wall thickness, smooth and continuous contours)

• Nasal cavity:

– Pneumatization

– Septum on midline

– Turbinates (presence of superior, middle, and inferior turbinates; width)

Orbit

• Configuration of orbital cone

• Contents:

– Globe (position—see below; size, density, wall thickness)

– Eye muscles (position, course, density, width)

– Optic nerve (course, width—see below)

– Ophthalmic vein (course, width—see below)

Calvarium

• Configuration

• Contours (smooth, sharp, no expansion or bony outgrowths, no osteolytic or osteoplastic areas)

Pituitary

The sella shows normal size, position, and configuration. The borders of its floor and walls are smooth and sharply defined.

The pituitary shows normal position, shape, and size. The pituitary tissue shows normal, homogeneous density both before and after contrast administration. It contains no circumscribed hypodense or hyperdense areas.

The infundibulum is centered and of normal size.

The optic chiasm and suprasellar CSF spaces appear normal. The cavernous sinus and imaged portions of the internal carotid artery and carotid siphon are unremarkable.

Evaluable portions of the neurocranium show no abnormalities.

The sphenoid sinus is clear and pneumatized.

Interpretation

The Pituitary appears normal.

Important Data

1 Pituitary:

a Height (in the midcoronal plane): 2–7 mm

Caution: allow for normal size variations during:

• Pregnancy: up to 12 mm

• Puberty: up to 10 mm in girls, up to 8 mm in boys

b Width (transverse extent in coronal plane, women of childbearing age): 12.9 mm ± 1.6 mm

Area of the pituitary in the coronal plane (height × width, women of childbearing age): 93 mm2 ± 1.6 mm2

2 Optic chiasm:

• Coronal: a, width 9–18 mm; b, height 3–6 mm

• Axial: c, width 12–27 mm; d, depth 4–9 mm

3 Pituitary stalk:

• < 4mm

Coronal scan

Axial scan

Checklist Sella

• Position

• Configuration (U shape)

• Walls steep, not splayed, of normal size

• Normal width of floor and walls

• Borders smooth and sharp

Pituitary

• Position:

– At the center of the sella

• Configuration:

– Bean-shaped

– Superior border straight or slightly concave (convex only during puberty or pregnancy)

• Size (see below)

• Density:

– Pituitary tissue homogeneous on noncontrast scans

– Homogeneous contrast enhancement

– No circumscribed hypodense or hyperdense areas within the pituitary

Infundibulum

• Position (centered)

• Size (see below)

Optic chiasm

• Position

• Size (see below)

• Symmetry

• Course of optic nerve

Suprasellar CSF spaces (chiasmatic cistern)

• Shape (symmetrical)

• Width (no circumscribed narrowing)

Cavernous sinus

• Shape (symmetrical)

• Size (see below)

• No infiltration

Internal carotid artery (siphon area)

• Size

• Course

• Density

Neurocranium

• Temporal lobe

• Hypothalamus

• Floor of third ventricle

Sphenoid sinus

• Borders: smooth, normal width (especially of roof), contours

• Pneumatization

Petrous Pyramids

The petrous pyramids are normally developed and symmetrical. They have smooth, intact cortical margins and a normal trabecular structure. The internal auditory canal is smooth and sharply defined on each side, with normal shape and diameter. The cochlea and semicircular canals appear normal. The mastoid air cells are normally developed, clear and pneumatized. Their bony walls are of normal thickness. The tympanic cavity is normally developed, and the auditory ossicles have a normal appearance.

Configuration of the cerebellopontine angle area on each side is normal, with clear delineation of the cerebellopontine angle cistern. The brain stem has normal configuration and CT density.

The external auditory canal appears normal on each side.

Other visualized portions of the neurocranium show no abnormalities.

Interpretation

Both petrous pyramids appear normal at CT.

Important Data

1 Internal auditory canal:

• Approx. 5–10 mm, with ca. 1 mm difference between the right and left sides

Axial scan through the internal auditory canal

Axial scan for evaluating the auditory ossicles

Coronal scan through the internal auditory canal

Orbit

The orbits are symmetrical and of normal size, with normal development of the orbital cone. The configuration of the smooth, sharply defined orbital walls is normal. There are no foci of bone destruction and there is no circumscribed widening of bony or soft-tissue components of the orbital walls.

The globes are symmetrical and show normal size and position. The ocular contents are of normal density. The ocular wall is smooth, sharply defined, and of normal thickness. The optic nerve shows a normal course and caliber on each side.

The eye muscles are normally positioned and display normal width and course. The retrobulbar fat and ophthalmic vein are unremarkable.

Imaged portions of the neurocranium and paranasal sinuses show no abnormalities.

Interpretation

The orbit and its contents appear normal.

Checklist Orbits

• Symmetrical

• Normal size

• Normal orbital cone

Orbital walls Globe

• Smooth, sharp borders

• No bone destruction

• No circumscribed widening of bone or softtissue components

Globe

• Position (see below)

• Symmetry

• Size (see below)

• Spherical

Ocular contents

• Density

Ocular wall

• Borders (smooth and sharp)

• Uniform thickness

Optic nerve

• Normal caliber (see below)

• Course

Eye muscles

• Position

• Width (see below)

• Course

Retrobulbar fat

• Clear

• No masses

Ophthalmic vein

• Course

• Caliber (see below)

Lacrimal gland

• Size

• Symmetry

• No unilateral or bilateral enlargement

• Position (see below)

• No excavation or destruction of adjacent bone

• Homogeneous internal structure

• No hypodense areas

• Smooth borders

Neurocranium

• Temporal lobes

• Frontal lobes

Paranasal sinuses

• Maxillary sinuses

• Ethmoid cells

Axial scan

Important Data

1 Diameter of globe:

• Axial plane:

– Right: 28.6 ± 1.2 mm

– Left: 29.4 ± 1.4 mm

• Sagittal plane (reconstruction):

– Right: 27.8 ± 1.2 mm

– Left: 28.2 ± 1.2 mm

2 Position of globe:

• Posterior margin is 9.9 mm ± 1.7 mm behind the interzygomatic line

3 Optic nerve (axial plane):

a Retrobulbar segment: 5.5 mm ± 0.8 mm

b Narrowest point (at approxinately mid-orbit): 4.2 mm ± 0.6 mm

4 Ophthalmic vein:

• 1.8 mm ± 0.5 mm (axial plane, 4 mm slice thickness)

• 2.7 mm ± 1 mm (coronal plane)

5 Eye muscles

a Superior rectus: 3.8 mm ± 0.7 mm

b Oblique: 2.4 mm ± 0.4 mm

c Lateral rectus: 2.9 mm ± 0.6 mm

d Medial rectus: 4.1 mm ± 0.5 mm

e